1. Field of the Invention
This invention relates to window assemblies, and in particular, to a window assembly having an emergency release mechanism adapted for quick and easy release of the window from a mounting structure.
2. Description of the Related Art
Window assemblies designed for mass transportation vehicles such as buses, motor coaches, and railroad passenger cars are often equipped with release mechanisms that provide for quick release of the window in emergencies. These window assemblies are typically hingedly mounted in the vehicle wall and latched in a closed position during normal operations. In emergencies, the window can be manually unlatched and pivoted outwardly to expose an opening through which passengers can exit from the vehicle.
Various emergency release mechanisms have been incorporated in window assembly designs for mass transportation vehicles. U.S. Pat. No. 4,313,280 entitled “QUICK OPENING LATCH ARRANGEMENT FOR HINGED VEHICLE WINDOWS” discloses a window construction having an emergency release mechanism that utilizes a release bar secured by a keeper mounted adjacent to the release bar. In this type of design, it is generally recognized that the release bar and keeper must be manufactured and installed to a tight tolerance for the mechanism to work properly. Moreover, any distortion and warping of the parts through use will greatly affect the operability of the release mechanism. U.S. Pat. Nos. 5,787,643 and 5,941,022 both entitled “WINDOW WITH LATCH ASSEMBLY” disclose a window assembly that utilizes a rotary latch to lock the window assembly in a closed position. The window assembly can be unlatched by raising a release bar that is operatively connected to the rotary latch. This design requires a person to apply sufficient force to overcome the frictional force between the release bar hinge and a leaf spring and cause a protrusion on the hinge to slide into a detent on the leaf spring. Disadvantageously, the amount of force required to raise the release bar cannot be easily adjusted as the required force is dictated by inherent design features such as the contact surface area and pressure between the release bar hinge and leaf spring.
Hence from the foregoing, it will be appreciated that there is need for a window assembly having a release mechanism that is adapted for easy and quick release of the window in emergencies. To this end, there is a particular need for a window assembly having an emergency release mechanism whereby the amount of force required to actuate the mechanism can be adjusted to suit a particular need.